Números 18:16

Y de un mes harás efectuar el rescate de ellos, conforme á tu estimación, por precio de cinco siclos, al siclo del santuario, que es de veinte óbolos.

And those that are to be redeemed from a month old shalt thou redeem, according to thine estimation, for the money of five shekels, after the shekel of the sanctuary, which is twenty gerahs.